Registration Dossier

Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Objective of study:
bioaccessibility (or bioavailability)
toxicokinetics
Test guideline
Qualifier:
according to guideline
Guideline:
other: US Food and Drug Administration Redbook II Guidelines (FDA, 1993).
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Taurine
EC Number:
203-483-8
EC Name:
Taurine
Cas Number:
107-35-7
Molecular formula:
C2H7NO3S
IUPAC Name:
2-aminoethanesulfonic acid

Test animals

Species:
rat
Strain:
not specified
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
deionised
Duration and frequency of treatment / exposure:
90 days once daily
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
600 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose / concentration:
treated animals: 12
contols: 6
Control animals:
yes, concurrent vehicle
Details on dosing and sampling:
TOXICOKINETIC / PHARMACOKINETIC STUDY (Absorption, distribution, excretion)
- Tissues and body fluids sampled (delete / add / specify): blood
- Time and frequency of sampling: Blood samples taken from 3 animals/sex/dose, at time 0 (immediately prior to dosing), 1, 2, 4, 8 and 24 hours following dosing on days 0 and 90 of the study for estimation of plasma taurine levels. Blood samples were collected from concurrent controls (6 animals/sex) on the same days at 0, 2 and 8 hours following dosing with vehicle.

Results and discussion

Toxicokinetic / pharmacokinetic studies

Toxicokinetic parametersopen allclose all
Key result
Test no.:
#1
Toxicokinetic parameters:
Cmax: at around 1 hour after dosing
Key result
Test no.:
#1
Toxicokinetic parameters:
other: Generally returning to baseline values by 24 hours. Plasma concentrations 24 hours after dosing were comparable with control values both on study day 0 and on day 90.
Key result
Test no.:
#1
Toxicokinetic parameters:
half-life 1st: less than 1 hour
Remarks:
initial half life
Key result
Test no.:
#1
Toxicokinetic parameters:
half-life 2nd: Plasma taurine levels 2 hours after dosing were 21-51% of the values measured at one hour.
Key result
Test no.:
#1
Toxicokinetic parameters:
half-life 3rd: ranged from 8.7 to 40 hours.
Remarks:
terminal half-life
Key result
Test no.:
#1
Toxicokinetic parameters:
AUC: Values were similar on study days 0 and 90.

Metabolite characterisation studies

Metabolites identified:
not specified

Applicant's summary and conclusion

Conclusions:
In the toxicokinetic study, plasma taurine levels increased in a dose-related manner, reaching peak Cmax values at around 1 hour after dosing and generally returning to baseline values by 24 hours.
Plasma taurine levels 2 hours after dosing were 21-51% of the values measured at one hour. Initial half-life was less than 1 hour and terminal half-life ranged from 8.7 to 40 hours.
Plasma concentrations 24 hours after dosing were comparable with control values both on study day 0 and on day 90. Area under the plasma-time concentration curve (AUC) values were similar on study days 0 and 90.
Both Cmax and AUC were proportional to dose. This study showed that taurine is readily bioavailable following oral administration and that it does not accumulate.